Glow discharge tube supply system



April I e. H. M. DANIEL 2,882,451

GLOW DISCHARGE TUBE SUPPLY SYSTEM Filed Feb. 27, 1957 3 Sheets-Sheet 1 HF var: j

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I Ihvenfr j Geo/385 HIM /W %,zid$4 PM April 14, 1959 G. H. M. DANIEL 2,882,451 GLOW DISCHARGE TUBE SUPPLY SYSTEM Filed Feb. 27, 1957 3 Sheets-Sheet 2 .Zm/cnfar Geo/ yes HMDd/i// flf f s April 1959 DANIEL I 2,882,451 GLOW DISCHARGE TUBE SUPPLY SYSTEM Filed Feb. 27, 1957 3 Sheets-Sheet 3 6 a 0599's b- MDa/we GLOW DISCHARGE TUBE SUPPLY SYSTEM Georges Henry Marie Daniel, Mazarques-Marseille, France, assignor to Societe Triflux, Marseille, France Application February 27, 1957, Serial No. 642,898

Claims priority, application Ih'ance March 16, 1956 15 Claims. (Cl. 315-166) This invention relates to glow discharge tube systems and more especially to supply circuits for such systems adapted to bring about a gradual energization of a glow discharge tube. A general object of the invention is to provide an improved glow discharge tube supply system of a special value in connection with the achievement of various lighting efiects for advertising, display and related purposes.

The supply system of the invention is of the general type wherein a variable-amplitude, high-frequency voltage is applied to one end of a glow discharge tube while the other end is held at a reference or zero potenial, and the amplitude of said voltage is graduallyvaried from zero to a maximum amplitude so as to illuminate the tube gradually, the glow discharge in the tube progressing continuously therethrough from said one end to the other end thereof.

An object of the invention is to provide for an improved smoothness or progressivity in the gradually increasing discharge in a system of the type just specified. Another object is to maintain the glow discharge excited after full illumination has been achieved with increased economy. A further object is to provide for selected illuminating sequences in systems including a plurality of glow tubes. Yet other objects will appear.

According to a basic aspect of the invention, there is provided in a glow discharge tube system, a source of A.-C. energy including an output coupling element, such as an inductance, a movable coupling element, e.g. inductance, in variable coupling'relation with said output element, and circuit means connected with said movable element and with said tube including resonant circuit' means selected to resonate at the frequency of said source, whereby the tube will be gradually illuminated on displacement of said movable element from a position of minimum coupling to a position of maximum coupling with said output element.

According to an important further aspect, the invention provides in such a system a stationary coupling element (e.g. inductance) in fixed coupling relation with said output element, and means for disconnecting the aforementioned circuit means from said variable coupling element and connecting said circuit means to said stationary coupling element substantially as said movable coupling element approaches or attains its maximum coupling position.

The above and further objects, features and advantages of the invention will appear as the disclosure proceeds with reference to the accompanying exemplary drawings which illustrate a few selected embodiments of the inventron.

Fig. 1 illustrates a basic circuit diagram of one embodiment of this invention;

Fig. 2 shows a modification of part of the circuit of Fig. 1, involving the output of the high-frequency generator;

Fig. 3 illustrates a circuit according to the invention for a plurality of tubes;

Fig. 4 shows a modification of part of the circuit involving the relay connections;

Fig. 5 illustrates a relay circuit arrangement in the case of a plurality of discharge tubes; and

Fig. 6 illustrates another modified relay circuit arrangement for a plurality of tubes.

Referring first to Fig. l, a circuit assembly according to the invention comprises a suitable generator device 1.

putting out a fixed, high frequency. The generator unit 1 may be of any conventional type, as a spark or are typegenerator, or one utilizing thermionic tubes or transistors.

The output frequency should be at least about 20 kilocycles, and desirably in the order of kilocycles. The generator output is fed to a tuned circuit comprising a capacity 2 and inductance 3 which may be connected in a parallel resonant circuit as shown in Fig. 1, or a series circuit as in Fig. 2, depending on the type of generator used.

Inductively coupled with the winding 3 are a movable inductance winding 4 and a fixed inductance 5.

The moving inductance 4, herein termed a variometer, is cyclically displaced, e.g. rotated, in variable inductive relation with the generator output Winding 3.

As shown, the variometer winding 4 has one end grounded and its other end connected by a lead 10 to one contact 12 of a relay switch controlled by a winding 9. The fixed winding 5 similarly has its one end grounded and its other end connected by a lead 11 to the other contact 13 of the relay switch. The movable armature of the relay switch is connected to one end of inductance 7 the other end of which is connected by way of capacitor 8 to ground. The glow discharge tube 6 has one end connected to the junction between inductance 7 and capacitor 8, and its other end connected to ground by way of a filtering condenser 15 shunting a rectifier diode 14. The relay'winding 9 is also connected in parallel across the condenser 15 and diode 14.

The capacitor 8 is so selected with regard to the combined inductance values of inductors 7 and 5 as to provide a resonant circuit therewith resonating at the generator output frequency.

The rectifier diode 14 may be of any suitable type, e.g. a thermionic diode tube, or a crystal rectifier of the germanium, silicon, copper oxide, selenium or other types.

The relay switch 12 13 is preferably of the makebefore-break or follow-through type wherein the contact 13 is established before the contact 12 is disengaged, so as to prevent a cutting off of the tube circuit as will later appear.

Operation is as follows. In the initial condition of the apparatus the upper contact 12 is closed as shown in the drawing, so that the inductance 7 is coupled with the generator output winding 3 by way of the variometer winding 4. The variometer winding is positioned in an initial null position normal to the generator output winding 3 so that zero voltage is induced in the variometer winding. To place the system in operation, variometer winding 4 is rotated by any suitable means, manually or automatically, from its starting position, so that the voltage induced in it gradually increases up to a maximum value produced when the winding 4 is parallel to the generator output winding 3. During this time the glow tube 6 progressively lights up, starting from its extremity connected to the winding 7. As the variometer coil 4 reaches its position parallel to winding 3, the high frequency energizing voltage becomes sufiicient to produce a complete illumination of the glow tube. At this time,

the rectified voltage present across the rectifier diode 14 and applied across relay winding 9 becomes high enough Patented Apr. 14, 1959 to actuate the relay armature and shift the switch from contact 12 to contact 13. The glow tube energizing circult is now supplied by way of the fixed winding in stead of being supplied by way of the variometer winding 4, and the tube ismai-ntained' in its ignited condition. The relay holds the contact 13 closed since the relay winding 9continues to be supplied with rectified voltage due to current flow through the glow tube. Matters are so arranged that at the time the circuit is switched from the ignite to the holdcondition, the voltage induced in windings 4 and 5 are not only substantially equal in amplitude, but are also in cophasal relationship.

Means may preferably be provided for cutting ofil the maintaining voltage from the discharge tube 6 and restoring the relay switch to its idle condition with contacts 12 engaged, as the variometer winding 4 again passes thrqugh its position normal to generator output winding; 5, so that the above described process can be repeated cyclically at a rate determined by the rate of rotation ofthe variorneter winding.

The circuitillustrated in Fig, 3 is designed to operate a pluralityof discharge tubes (only the first two of which are shown), with the tubes being ignited in succession and thereafter maintained illuminated. Referring to Fig. 3, there are here provided two variometer windings 4a and 4b, which may be mounted on a common or on separate shafts rotated at uniform or non-uniform rate or rates. Alternatively the variometer windings 4a and 4b may be angularly reciprocated about their axes between end positions spaced apart by an angular displacement of e.g. 90, or less or more; Whatever the particular type of motion imparted to the two variometer windings, rotational or reciprocatory; their displacements will generally be cyclical. These cyclical displacements however should not be in phase with each other, and the relative phase displacement between the two motions may be held constant, or it may itself be cyclically varied according to some preselected law, by any suitable mechanical or electrical means. In a particularly simple embodiment the variometer windings may be mounted on acommon shaft driven in rotation or angular reciprocation, and the constant phase displacement between the two motions of the two windings will then be determined by the angular displacement between the windings upon the common mounting shaft. Alternatively, the windingsmay be mounted on separate shafts connected with each other through suitable gearing, e.g. with a one to one drive ratio, or through any, suitable leverage or linkage achieving a similar result. In cases where particular illumination effects are desired; the phase displacement between the two variorneter; windings may be cyclically varied according to a selected law as already mentioned, and this may be accomplished by mountingthe two windings on separately driven shafts the relative angular positions of which may be controlled by means of a camsystem, a dilferentialsystem, or the like.

Electrical rather than mechanical means may be used for driving the variometer windings according to the selected law of-motion. Thus the two windings may be separately driven from individual synchronous motors and their relative positions may be varied by acting on.the phase conditions of said motors.

Associated with the variometer device is a rotary distributor switch 16 comprising four contact segmentsthe diametrically opposite ones of which are connected in pairs, as shownf Each of the variometer windings 4a and: 4b has one end connected to ground and. its other endconnectedto a related one of the two pairs of interconnected contact segments. The rotary switch 16 is bodily rotated in synchronism with the rotation of the,

variorneter assembly, so that its four contact segments.

ride pasta stationary wiper constituting the terminal of the lead 10. Thus it will be seen that the yariablearn- 4 plitude high frequency voltages induced in the variometer windings are successively applied to the lead 10. The rotary switch 16 may be of any suitable type, e.g. the type conventionally used in D.-C. generator collector assemblies, radio contact switches, cam-actuated spring switches, or the like purposes.

Each of the discharge tubes 6, 6a, is connected in a supply circuit similar to the one shown for the single tube 6 in Fig. l, and corresponding elements have been designated with the same reference numerals as in Fig. 1, followed by the suffix letters for each additional tube circuit after the first (only one additional tube is illustrated in Fig. 3 but any desired number may be pro vided). However, the relay switch operated by relay coil such as 9, herein comprises a, pair of ganged armaturcs 17 and 18 instead of a single armature as in Fig. l. The armature 17 corresponds to the single armature of the relay shown Fig. 1 and acts, to shift the circuit connections between a, lower QQntact 19. connected by way of lead 11 with the stationary winding 5, and an upper contact 26 connected, by way of lead 10 and the rotary switch described above with one or the other of the two variometer windings. The, upper armature 18 operates to shift the contact between lower contact 21 connected in common with contact 20, and an upper contact 22 connected by way of lead 10a to. the contact 20 of the next tube circuit. The system operates as follows:

Assume that at a given instant of time the variometer winding 4a is connected by way of distributor switch 16 and line 10 to the contact 20, as shown in the drawing. The tube 6 is supplied. with voltage and its illumination increases. During this time the contacts 19 and 22 are inoperative. When the tube 6 is fully energized, the voltage across the relay winding 9 becomes high enough to operate the, relay and the armatures 17 and 18 are moved downwardly into engagement with contacts Hand 21 respectively. A holding or maintaining circuit is now established for tube 6. from fixed winding 5, by way of line 11 and contact 19. The relay winding 9 remains energized and holds contacts 19 and 21 in engaged condition.

Closure of contacts -21 now establishes a circuit from the distributor switch, by. way of lines 10 and 10a, to the contact 20aof the circuit of the next tube of the series, so that this tube 6a is, now. progressively energized from variometcr, winding 4b, and. a similar sequential operation, setsin, until the tube. 6a. is fully energized andfits associated relay. 9a, is. energized, whereupon the tubeon is switched to its maintaining supply circuit from fixed. Winding 5, and the variometer voltage is now applied by way offdistributor switch 16, and lines 10, 10aand 10b, to the next following tube circuit. This type of operation will proceed until all of the glow tubes provided have been brought to a fully illuminated condition. The relay associated with, the last tubeof the series may be providedwith timedelay means, and is arranged on energization to cut off the supply circuitv for generator 1. The tubes are now all extinguished and the various relays are deenergized. and restored to their idle positions; this reestablishes. the circuit for generator 1 and thesame cyclic operation may be resumed.

In the forms of the invention so far described, the operation of the relayssuch as 9 was controlled by the amplitude level of the alternating voltage present acrossv the respective discharge tubes. In a. modified form of the invention illustrated in Fig. 4, the relay operation may be determined by the voltage level present on the leads such as 10, 10a. Thus, as shown in Fig. 4, the tube 6 is grounded directly while the rectifier 14 with; relay, winding 9 in parallel therewith is connected. between ground and. the armature, 17 of; the relay. The. dis:

tributor switch arrangement described with reference to;

Fig. 3 may be retained unaltered in the modified circuit of Fig. 4.

According to a further modification, there may be associated with the rotary distributor switch 16 an arrange ment of contact switches adapted to supply voltage pulses over one or more lines to the tube circuits, in order to achieve any desired lighting effects.

Fig. 5 illustrates by way of example one embodiment of this modification of the invention. As shown, the supply lines A and B may represent an AC. or D.-C. supply. A contact switch associated with the variometer is indicated at 25, and may form part of a rotary distribution switch of the type shown at 16 in Fig. 3. Each relay comprises a winding 26 operating four armatures 27, 28, 29 and 44, respectively cooperating with the idle contacts 31, 33 and 35 and the operative lower contacts 30, 32, 34 and 45. Contact 35 is connected by line 36 to the variable high-frequency voltage and contact 34 is connected by line 37 with the fixed high-frequency voltage. The armature 29 is connected to one end of tube 6 and armature 28 is connected with the contacts 31a, 32a of the relay associated with the next tube 6a. Armature 44 is connected with the contacts 35a45a of the relay associated with tube 6a.

With the switch open, the relay 26 is deenergized and tube 6 is supplied with the variable high frequency voltage. On switch 25 being closed, e.g. due to the aforedescribed operation of the distributor switch, winding 26 is energized by Way of contact 31 and armature 27. The armatures 27, 28, 29 and 44 are now moved away from the contacts 31, 33 and into engagement with the contacts 30, 32, 34 and 45. Engagement of armature 27 with contact 30 completes a holding circuit for the relay. Engagement of armature 28 with contact 32 connects the line in which switch 25 is inserted, with the contacts 31a and 32a of the following stage relay which is thus caused to initiate a similar operating cycle.

Engagement of armature 29 with contact 34 cuts off the variable alternating energy supply from tube 6 and connects the fixed alternating energy supply thereto. The ultimate relay of the series then causes the opening of the switch contact 39, whereupon all of the relays are restored to their idle conditions.

As previously indicated, the operation of the various relays should be such that the voltage supply will not be temporarily cut off during the movement of the armatures from the upper to the lower relay contacts. To ensure this, relays of the make-before-break type may be used or, as shown in Fig. 5, shunt capacities such as 46 may be provided across the relay windings.

To ensure satisfactory operation of the described system, the relay should preferably be provided with a delayed closure time of the order of half a second or so, and the duration of the voltage pulse should preferably be provided in a range of from one half second to one second. For this purpose any suitable time delay means may be used as is well known in the art, and/ or auxiliary timing relays may be employed.

The circuit of Fig. 6 illustrates yet another switching arrangement according to the invention. The essential difference from the arrangement just described is that the switching relays are divided in two groups, an odd and an even group. The odd group relays are controlled through switch contact 25 which may be associated with the variometer winding 4a and the even group relays are controlled through the switch contact 25a associated with variometer winding 4b.

With this arrangement it will be apparent that the switch contacts 25 and 250 may be alternately energized to energize the windings 26 of the odd group relays and windings 26a of the even group relays in alternating sequence. As a result a glow tube of odd denomination may be gradually illuminated prior to the application of maintaining voltage to a glow tube of even denomination, or vice-versa. Another possbility had with this arrangement is that the odd relay circuits may be cut off by the even relays, through contacts such as 40 and armatures such as 41, or vice versa. With this arrangement therefore any undesired deenergization may be positively prevented even if instantaneous-acting relays are used. Thus, the armature 41a of an odd group relay is connected to the contacts 31b-32b of the next following even group relay. The armature 28a of an odd group relay is connected to contact 40b of the next following even group relay for connecting said relay to the line 42 controlled by the contacts 25-25a.

It will be understood that the invention is by no means limited to the particular circuit arrangements illustrated and described. Among many other possible modifications, the variometers and the fixed maintaining voltage winding may be coupled to the output of a single highfrequency generator (as shown in Fig. 1) or they may be separately coupled to the outputs of different generators. The number of windings coupled to the output of the generator or generators may be greater or less than the three shown, depending on the particular illumination effects desired.

What I claim is:

1. In a glow discharge tube system, in combination, a glow discharge tube, a source of high frequency energy including an output coupling element, a movable coupling element in variable coupling relationship with said output element, a resonant circuit connected with said movable coupling element and with said tube and resonating at the frequency of said source, and means for displacing said movable element relative to said output element between a minimum and a maximum coupling position, whereby a variable amount of said energy is transferred over said resonant circuit to said tube to bring said tube from a substantially extinguished to a substantially fully illuminated condition.

2. In a glow discharge tube system, in combination, a glow discharge tube, a source of alternating energy including an output coupling inductance, a movable inductance in variable coupling relation with said output inductance, and a circuit connected with said movable inductance and with said tube including resonant circuit means selected to resonate at the frequency of said source whereby said tube will be gradually illuminated on displacement of said movable inductance from a position of minimum coupling to a position of maximum coupling with said output inductance.

3. In a glow discharge tube system in combination, a glow discharge tube, a source of A.-C. energy including an output coupling element, a stationary coupling element in fixed coupling relation with said output element, a movable coupling element in variable coupling relation with said output element, a resonant circuit connected with said tube and adapted to resonate at the frequency of said source, and circuit means including a switch adapted in a first switch position to connect said resonant circuit with said movable element and in another switch position to connect said resonant circuit with said stationary element, means displacing said movable element from a minimum to a maximum coupling position relative to the output element, and means operative to shift: said switch from its first to its second position substantially as said movable element attains its maximum coupling position, whereby said tube is gradually illuminated by application of voltage from said movable element, and is then maintained in illuminated state by application of voltage from said stationary element.

4. In a glow discharge tube system in combination, a glow discharge tube, a source of A.-C. energy including an output inductance, a stationary inductance in fixed coupling relation with said output inductance, a rotatable inductance in variable coupling relation with the output inductance, a resonant circuit connected with the tube and turned to the source frequency, switch means adapted in a first position to connect said circuit with said rotatable inductance and in a second position to connect said circuit with said stationary inductance, means rotating said rotatable. inductance between a position normal and a position parallel to said output inductance, and means operative to shiit said; switch from its first to its second position substantially as said rotatable inductance reaches its said parallel position.

5. In a. glow discharge tube system in combination, a glow discharge tube, a source of A.-C. energy including an output element, a stationary coupling element in fixed coupled relation with said output inductance, a movable coupling element in variable. coupled. relation with said output element, a resonant circuit connected with the tube and tuned to the source. frequency, switching means put element, and means responsive to the flow of cur-- rent through said circuit shift said switch from its first to its second position as the current flow exceeds a predetermined value.

6. A glow discharge system as claimed in claim 5, wherein said current flow responsive means comprise a relay winding operating said switch.

7. A glow discharge system as claimed in claim. 5, wherein said current flow responsive means comprise a relay winding operating said switch, and rectifier means connected with said circuit and said relay-winding'to energize said winding with direct voltage to operate said switch when the. alternating current through said circuit has exceeded said predetermined value.

8. In a glow discharge system as claimed in claim 4, means for continuously rotating said rotatable inductance.

9. In a glow discharge system as claimed in claim 4, means for reciprocatingly rotating said rotatable inductance between angularly displaced positions.

10. In a system comprising at least two glow discharge tubes, a source of alternating energy including an output element, a first andv a second movable coupling elements in variable coupling relation with said output ele ment, resonant circuit means. connected with each tube and each tuned to the frequency of said source, means cyclically displacing saidv movable elements relative to the output element in mutually displaced relation, and distributor switch means operative during said cyclic displacementsequentially to connectsaid circuit means first with one then withthe. other of said movable coupling elements to, produce. a; sequential gradual illumination of said tubes.

1.1. In a system comprising atlcast two glow discharge tubes, a. sourceof A.-C. energy including an output element, a stationary coupling element in fixed coupling relation with said output element, a first and at least a second movable coupling elements in variable coupling relation with said output element, resonant circuit means connected with each tube and each tuned to the frequency of said source, means cyclically displacing said movable elements relative to the output element in mutually singularly-displaced relatiom. distributor switch means operative during said cyclic: displacement sequentially to connect said circuit'means' first with one then with the other of said coupling elements. to produce a sequential gradual illumination of said tubes, and means resonant sive to the current flow through each of said resonant circuits to connect said circuit to said fixed coupling element upon said current flow exceeding a predetermined value.

12. A system as claimed in claim 11, wherein said current flow responsive means comprise a relay winding, rectifier means connected with said circuitand said winding to energize the winding with rectified voltage when the alternating current through said circuit exceeds a predetermined value, first switch means operated bysaid relay winding to connect said circuit to said: fixed coupling element and. second switch means operated by said relay winding to connect the resonant circuit of. the next following discharge tube to one or the other of said variable coupling elements through said distributor switch.

13. In a system comprising a plurality of glow discharge tubes, a source of A.-C. energy including an output element, a stationary coupling element in fixed coupling relation with said output element, at least two movable coupling elements in variable coupling relation with said output clement, resonant circuit means connected with each tube and each tuned to the frequency of said source, means cyclically displacing said movable elements relative to the output element in mutually angularly-displaced relation, distributor means operative during said cyclic displacement sequentially to connect each of said resonant circuits with said stationary coupling element and with selected ones of said movable coupling elements according to a pred'eterminedsequencc to produce a sequential gradual illumination of said plurality of tubes and hold each tube illuminated.

14. A system as claimed in claim 13,. wherein said distributor means comprise a rotary distributor switch operated in synchronism with said movable elements, and relay means respectively associated with said resonant circuits.

15. A system as claimed in claim 13, wherein said movable coupling elements are two in number and wherein said tubes and associated. resonant circuits are divided into two groups, and said sequence is predetermined to producev anxalternating illumination of a tube of each of said groups.

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